1. A sample of 10 high school students completed a course designed to increase SAT verbal scores. The following is the summary for this group’s SAT verbal scores after completion of the course: Σx= 5846, Σx2 =3428148.
a. What is the mean and standard deviation for this groups’ SAT verbal score?
b. What scores mark the cutoff for the most deviant 10%?
c. In the past, students have had an average SAT verbal score of 542. Can the school accurately conclude that this new course significantly improved the SAT verbal scores of these 10 students? Write both a statistical statement and an English statement
d. If a student made a 500 on this SAT, what would be his/her percentile rank?
2. Time to complete complex math problems while listening to music was investigated using 16 high school students. Students were matched on their math gpa, then randomly assigned to either the Country Western music group or the Classical music group.
a. Conduct the appropriate analysis to determine if there was an effect of the music on completing problems
b. Construct the appropriate graph to show the differences in the scores of the two groups.
Country Western Classical
26
21
10
25
20
15
14
10
14
15
10
8
12
10
7
5
3. Student volunteers in a weight loss project were randomly assigned to one of three diets. After 2 months on the diets, subjects were weighed and weight loss was recorded for each person.
a. Conduct a test to determine if there was a significant effect of the diets. Include both analysis and graph (
b. Create the appropriate graph for the diet data below(
Diet A Diet B Diet C
7
9
8
12
8
7
4
10 9
6
10
13
9
11
5
9
8
10 8
7
12
11
15
7
14
12
10.
11
4. Young married couples are asked to complete a “Love & Respect” survey (higher scores indicate positive attitude) before and after completion of a six week marriage enrichment course taken through their church. A composite respect score for the couple is shown below.
a. Conduct the appropriate test to determine if there was a significant effect of the course on respect scores
b. Construct the proper graph to show change, if any, in the score.
Couple Before After
1
2
3
4
5
6
7
8
9
10 18
17
12
15
10
18
16
15
12
14 22
21
20
25
24
26
22
20
19
20
5. Time to help a stranger was investigated by a group of undergraduate psychology majors as a part of their Introduction to Research Methods course. The students thought that gender of the person asking for help would be a factor, as would the dress of the person asking for help. So to investigate this, the students staged a car problem on a busy parking lot at the mall. One male and one female student (dressed casually but neatly) and another male and female (dressed grunge) acted as if their car wouldn’t start. Other students sitting in their own cars clocked the length of time (in minutes) a stranger would attempt to help these four actors.
a. Conduct the appropriate analysis to determine if there were significant effects of gender and dress
b. Construct the appropriate graph and interpret
Casual Male Female
14
11
12
25
20
25
15
Grunge 8
12
8
8 8
5
7